To summarize from the docs, config servers store the metadata for a sharded cluster, and /data/configdb is the default path where a config server stores its data files. So if you're not dealing with sharded clusters, removing any references to it should be ok.

From the docs:

--configsvr

Declares that this mongod instance serves as the config server of a sharded cluster. When running with this option, clients (i.e. other cluster components) will not be able to write data to any database other than config and admin. The default port for a mongod with this option is 27019 and the default --dbpathdirectory is /data/configdb, unless specified.

References:

https://docs.mongodb.com/manual/core/sharded-cluster-config-servers/

https://docs.mongodb.com/v3.4/reference/program/mongod/#cmdoption-configsvr

Hope this helps!

I have deployed docker image of mongodb https://hub.docker.com/_/mongo on OpenShift it generated out of the box the deployment.yaml file which contains part with two volumeMounts:

 - mountPath: /data/configdb
   name: mongo-5-0-1
 - mountPath: /data/db
   name: mongo-5-0-2

When I want to use single not sharded database server and store my data into volume, this is how this part of deployment.yaml should look like

  volumes:
    - name: mongo-5-0-1
      emptyDir: {}
    - name: mongo-5-0-2
      persistentVolumeClaim:
        claimName: myVolumeName 
        

In image documentation it's mentioned that:

This image also defines a volume for /data/configdb for use with --configsvr (see docs.mongodb.com for more details).